Structure of Debaryomyces castellii CBS 2923 phytase

Phytate (myo-inositol hexakisphosphate) is the primary storage form of phosphate in seeds and legumes (Reddy et al., 1982). Phytases are phosphatases that hydrolyze phytate to less phosphorylated myo-inositol derivatives and inorganic phosphate. The crystal structure of phytase from Debaryomyces castellii has been determined at 2.3 Å resolution. The crystals belonged to space group P6₅22, with unit-cell parameters a = 121.65, c = 332.24 Å. The structure was solved by molecular replacement and refined to a final R factor of 15.7% (R_free = 20.9%). The final model consists of a dimer (with two monomers of 458 residues), five NAG molecules and 628 water molecules.